JP2019178818A - Liquid cooling device and maintenance method of liquid cooling system - Google Patents

Abstract

To provide a liquid cooling device in which a condenser is easily maintained.SOLUTION: The liquid cooling device comprises: a refrigerant circuit in which a compressor (1), a condenser (3), an electric expansion valve (EV) and an evaporator (4) are annularly connected; a four-way switch valve (2) switching a refrigerant circulation direction of the refrigerant circuit from a normal cycle to a reverse cycle; a control device (20) controlling the refrigerant circuit and the four-way switch valve (2); and a housing (11) in which the refrigerant circuit, the four-way switch valve (2) and the control device (20) are housed. The condenser (3) is detachably attached to the housing (11). The refrigerant circuit has, at a housing (11) side, closing valves (V1, V2) closing a refrigerant pipe connected to the condenser (3). The control device (20) controls the four-way switch valve (2) and the refrigerant circuit before detaching the condenser (3) from the housing (11) to switch the refrigerant circulation direction of the refrigerant circuit to a reverse cycle, and then starts the compressor (1) to perform a pump-down operation to store the refrigerant at an evaporator (4) side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid cooling device.

  Conventionally, a liquid cooling device includes a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are annularly connected, and a blower fan that supplies air to the condenser. There is a type in which lubricating oil (hereinafter referred to as “working fluid”) is cooled by an evaporator (see, for example, JP-A-2015-68524 (Patent Document 1)).

Japanese Patent Laying-Open No. 2015-68524

  In the above-mentioned liquid cooling device, when used to cool grinding fluid and lubricating oil of a main machine such as a machine tool, a filter is disposed on the front surface of the condenser, and oil mist and dust are captured to capture the oil to the condenser. Prevents adhesion.

In the above-mentioned liquid cooling device, if the trapping performance of the filter is increased, the pressure loss increases and the cooling performance decreases, so the filter mesh cannot be made fine, and oil mist and dust adhere to the condenser. To do. For this reason, in the liquid cooling device, not only a filter that can be easily removed and cleaned, but also the condenser needs to be cleaned periodically.

In such a liquid cooling device, when the filter starts to be clogged, it proceeds at an accelerated rate, so that the cleaning cycle of the filter and the condenser becomes very short.

  In the above liquid cooling device, since it is necessary to remove the entire device from the installation place when cleaning the condenser, maintenance takes time, and during this time, the main unit cannot be operated, so the operating rate of the main unit also decreases.

  The present disclosure proposes a liquid cooling apparatus and a liquid cooling system maintenance method that facilitate maintenance of the condenser.

The liquid cooling device of the present disclosure is:
A refrigerant circuit in which a compressor, a condenser, a decompression mechanism, and an evaporator are connected in an annular shape;
A four-way switching valve for switching the refrigerant circulation direction of the refrigerant circuit from a forward cycle to a reverse cycle;
A control device for controlling the refrigerant circuit and the four-way switching valve;
A housing containing the refrigerant circuit, the four-way switching valve and the control device;
The condenser is detachably attached to the casing,
The refrigerant circuit has a closing part on the housing side for closing a refrigerant pipe connected to the condenser,
The controller controls the four-way switching valve and the refrigerant circuit before removing the condenser from the housing, and switches the refrigerant circulation direction of the refrigerant circuit to a reverse cycle. A pump-down operation is performed in which the compressor is started and the refrigerant is accumulated on the evaporator side.

  According to the present disclosure, before removing the condenser from the housing, the controller controls the four-way switching valve and the refrigerant circuit to switch the refrigerant circulation direction of the refrigerant circuit to the reverse cycle, and then the compressor By starting the pump and performing a pump-down operation in which the refrigerant is accumulated on the evaporator side, the condenser can be removed from the housing without the refrigerant in the condenser, and the condenser can be easily maintained. it can.

Moreover, in the liquid cooling device according to one aspect of the present disclosure,
A liquid pump for circulating the liquid to be heat-exchanged in the evaporator through a circulation path;
The liquid pump is operated during the pump down operation.

  According to the present disclosure, during the pump-down operation, the liquid pump is operated to circulate the liquid heat exchanged in the evaporator via the circulation path, so that the cold heat of the liquid flowing in the circulation path is recovered by the evaporator. It can be used to condense refrigerant and reduce pump down operation time.

Moreover, in the liquid cooling device according to one aspect of the present disclosure,
Arranged in a liquid tank in which the liquid to be heat-exchanged in the evaporator circulates, and equipped with a liquid stirring unit for stirring the liquid in the liquid tank;
The said control apparatus controls the said liquid stirring part, and operates the said liquid stirring part at the time of the said pump down driving | operation.

  According to the present disclosure, the liquid agitating unit is controlled by the control device, the liquid agitating unit is operated during the pump down operation, and the liquid in the liquid tank in which the liquid to be heat-exchanged in the evaporator circulates is agitated. The cold heat of the liquid flowing through the circulation path can be efficiently used for the condensation of the refrigerant in the evaporator.

In addition, the maintenance method of the liquid cooling system of the present disclosure is:
A maintenance method for a liquid cooling system including the liquid cooling device according to any one of the above,
Performing a pump-down operation in which refrigerant is accumulated on the evaporator side by the control device;
After the pump down operation, closing the closing part and removing the condenser from the housing;
Washing the condenser removed from the housing;
Attaching the cleaned condenser to the housing and opening the closing portion.

  According to the present disclosure, after the pump-down operation in which the control device stores the refrigerant on the evaporator side, the closed portion is closed, the condenser is removed from the housing, the removed condenser is washed, and the washed condenser is removed. The condenser can be easily maintained by attaching it to the housing and opening the closing portion.

In the maintenance method for the liquid cooling system according to one aspect of the present disclosure,
A liquid pump for circulating the liquid to be heat-exchanged in the evaporator through a circulation path;
Before the step of performing the pump-down operation, the liquid pump is operated with the four-way switching valve in a state where the refrigerant circulation direction of the refrigerant circuit is a positive cycle, and the liquid flowing through the circulation path is discharged. Pre-cooling with the evaporator,
In the step of performing the pump-down operation, the liquid pump is operated to use the cold heat of the liquid flowing through the circulation path for the condensation of the refrigerant in the evaporator.

  According to the present disclosure, during the pump-down operation, the liquid pump is operated to circulate the liquid heat exchanged in the evaporator via the circulation path, so that the cold heat of the liquid flowing in the circulation path is recovered by the evaporator. It can be used to condense refrigerant and reduce pump down operation time.

It is a schematic block diagram of the liquid cooling device of 1st Embodiment of this indication. It is a perspective view of the said liquid cooling device. It is a perspective view of a liquid cooling device in the state where a condenser was removed. It is a flowchart explaining operation | movement of the control apparatus of the said liquid cooling device, and washing | cleaning operation | work. It is a flowchart explaining the operation | movement of the cooling operation of the working fluid of the said control apparatus. It is a flowchart explaining the operation | movement of the pump down driving | operation of the said control apparatus. It is a schematic block diagram of the liquid cooling device of 2nd Embodiment of this indication. It is a perspective view of the said liquid cooling device.

  Hereinafter, embodiments will be described. In the drawings, the same reference numerals represent the same or corresponding parts. In addition, dimensions on the drawing such as length, width, thickness, and depth are appropriately changed from actual scales for clarity and simplification of the drawings, and do not represent actual relative dimensions.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a liquid cooling apparatus 10 according to the first embodiment of the present disclosure. The liquid cooling device 10 cools the working fluid while circulating the working fluid of the machine tool 100 through the oil tank T. The oil tank T is an example of a liquid tank.

  As shown in FIG. 1, the liquid cooling apparatus 10 of the first embodiment includes a refrigerant circuit in which a compressor 1, a condenser 3, an electric expansion valve EV and an evaporator 4 are annularly connected, and refrigerant circulation in the refrigerant circuit. A four-way switching valve 2 that switches the direction from a forward cycle to a reverse cycle, a blower fan 6 that supplies air to the condenser 3, and a control circuit 20 that controls the refrigerant circuit, the four-way switch valve 2, and the blower fan 6. ing. The electric expansion valve EV is an example of a pressure reducing mechanism.

  The discharge side of the compressor 1 is connected to the first port 2 a of the four-way switching valve 2. The second port 2 b of the four-way switching valve 2 is connected to one end of the condenser 3 via the closing valve V <b> 1 and the pipe connection part 15. The other end of the condenser 3 is connected to one end of the electric expansion valve EV through the pipe connection portion 16 and the closing valve V2. The closing valves V1 and V2 are an example of a closing portion.

  In addition, the other end of the electric expansion valve EV is connected to one end 4 a of the evaporator 4. Further, the other end 4 b of the evaporator 4 is connected to the third port 2 c of the four-way switching valve 2. Further, the fourth port 2 d of the four-way switching valve 2 is connected to the suction side of the compressor 1 via the accumulator 5.

  Further, the other end of the pipe L <b> 1 whose one end is immersed in the working fluid in the oil tank T is connected to the inflow port 4 c of the evaporator 4. A circulation pump P is disposed in the pipe L1. This circulation pump P is an example of a liquid pump.

  Further, one end of the pipe L <b> 2 is connected to the outflow port 4 d of the evaporator 4, and the other end of the pipe L <b> 2 is connected to the machine tool 100.

  The oil tank T, the pipe L1, the evaporator 4, the pipe L2, the machine tool 100, and the pipe L3 constitute a circulation path through which the working fluid circulates.

  The liquid cooling device 10 and the circulation path constitute a liquid cooling system. In the first embodiment, the liquid cooling device 10 is provided with the circulation pump P (liquid pump). However, the liquid cooling device is provided with a liquid pump separately from the liquid cooling device, and the liquid cooling is performed by the liquid cooling device, the liquid pump, and the circulation path. A system may be configured.

  FIG. 2 is a perspective view of the liquid cooling apparatus 10. As shown in FIG. 2, the liquid cooling device 10 includes a vertically long rectangular parallelepiped casing 11. A suction port 12 is provided on one side surface of the housing 11, and a net-like filter 13 is attached to the suction port 12. In FIG. 2, 14 is a blower outlet.

  FIG. 3 is a perspective view of the liquid cooling device 10 with the condenser 3 removed. In FIG. 3, the net-like filter 13 of the suction port 12 is removed. In FIG. 3, 31 is a handle provided in the condenser 3.

  As shown in FIG. 3, the condenser 3 is detachably attached to the housing 11. The housing 11 has closing valves V1 and V2 (closing portions) for closing the refrigerant pipes connected to the condenser 3, and after closing the refrigerant in the evaporator 4 by pump-down operation, the closing valves V1 and V2 are closed. By doing so, it becomes possible to remove the condenser 3 from the housing 11.

  In this case, the condenser 3 is in a state in which no refrigerant is contained, and does not need to be handled as a pressure vessel, so that the handling becomes easy.

  In the working fluid cooling operation of the liquid cooling device 10, the high-pressure gas refrigerant discharged from the compressor 1 flows into the condenser 3 through the four-way switching valve 2, and heat is exchanged with the outside air in the condenser 3. It becomes liquid refrigerant by condensing. Next, the liquid refrigerant depressurized in the electric expansion valve EV flows into the evaporator 4 and exchanges heat with the working fluid to evaporate to become a low-pressure gas refrigerant, and the suction side of the compressor 1 via the accumulator 5 Return to. Thereby, the working fluid is cooled in the evaporator 4. In this working fluid cooling operation, the control device 20 controls the rotational frequency of the compressor 1 and the opening of the electric expansion valve EV based on the temperature of the working fluid, the room temperature, and the like.

  Next, a maintenance method for the liquid cooling system including the liquid cooling device 10 will be described with reference to FIGS.

  FIG. 4 is a flowchart for explaining the operation and cleaning operation of the control device 20 of the liquid cooling device 10. In FIG. 4, operation | movement of the control apparatus 20 in the maintenance of the condenser 3 is shown on the left side, and the content of work is shown on the right side.

  First, as shown in FIG. 4, the control device 20 performs a cooling operation of the working fluid in step S <b> 1 by an operation by an operator. Thereby, the temperature of the working fluid is lowered in advance before performing the pump-down operation. In this case, the machine tool 100 which is the main machine is in a stopped state.

  Next, it progresses to step S2 and the circulation pump P is drive | operated. Thereby, the working fluid in the oil tank T circulates through the pipe L1, the evaporator 4, the pipe L2, the machine tool 100, and the pipe L3.

  Next, it progresses to step S3 and a pump down operation is performed. Thereby, the refrigerant in the refrigerant circuit is collected in the evaporator 4.

  After completion of the pump-down operation, the process proceeds to step S4 and the circulation pump P is stopped.

<Working>
In step S <b> 11, the operator removes the condenser 3 from the casing 11 by removing the pipe connection parts 15 and 16. Here, the shut-off valves V1, V2 are closed in the pump-down operation in step S3.

  In step S12, the removed condenser 3 is washed.

  Next, the cleaned condenser 3 is attached to the housing 11. At this time, the condenser 3 is connected to the refrigerant circuit via the pipe connection parts 15 and 16.

  Next, the closing valves V1, V2 are fully opened. Thereby, the washing | cleaning of the condenser 3 is complete | finished. Note that the removed filter 13 is also cleaned in the same manner as the cleaning of the condenser 3.

  FIG. 5 is a flowchart for explaining the operation of cooling the working fluid in step S1 shown in FIG.

  When the process of cooling the working fluid starts, the operation of the compressor 1 is started in step S21.

  Next, it progresses to step S22 and the circulation pump P is drive | operated.

  Next, it progresses to step S23 and the opening degree of the electric expansion valve EV is controlled according to the temperature of the evaporator 4 or the temperature of a working fluid.

  Next, the process proceeds to step S24, and if it is determined that the temperature of the working fluid has become equal to or lower than a predetermined temperature t1 (for example, 10 ° C.), the process proceeds to step S25, while the temperature of the working fluid is higher than the predetermined temperature t1 (for example, 10 ° C.). If it is judged, it returns to Step S23 and repeats Steps S23 and S24.

  In step S25, the compressor 1 is stopped.

  Next, it progresses to step S26, the circulation pump P is stopped, and the process of the cooling operation of a working fluid is complete | finished.

  FIG. 6 is a flowchart for explaining the pump-down operation in step S3 shown in FIG.

  When the pump down operation process is started, the coil of the four-way switching valve 2 is excited in step S31 to switch the refrigerant circulation direction of the refrigerant circuit to the reverse cycle.

  Next, it progresses to step S32 and fully closes the electric expansion valve EV.

  Next, it progresses to step S33 and the driving | operation of the compressor 1 is started. As a result, the refrigerant circulation direction of the refrigerant circuit is reversed, and the refrigerant accumulates in the evaporator 4 and the liquid refrigerant condensed in the evaporator 4 is recovered.

  Next, the process proceeds to step S34, and if it is determined that a predetermined time has elapsed since the start of operation of the compressor 1, the process proceeds to step S35, while if it is determined that the predetermined time has not elapsed since the start of operation of the compressor 1, step S34. repeat.

  In step S36, the compressor 1 is stopped.

  Next, it progresses to step S37 and the coil of the four-way selector valve 2 is de-energized and returned. That is, the four-way switching valve 2 is switched so that the refrigerant circulation direction of the refrigerant circuit becomes a positive cycle.

<Working>
In step S40, the operator closes the shut-off valves V1 and V2 from the start of operation of the compressor 1 in step S33 until the refrigerant recovery is completed and a predetermined time elapses.

  In the first embodiment, the end of the pump-down operation is the time when a predetermined time has elapsed from the start of the operation of the compressor 1, but the end of the pump-down operation is based on the outside air temperature, the temperature of the evaporator 4, and the like. The pump down operation may be terminated.

  According to the maintenance method of the liquid cooling device 10 and the liquid cooling system having the above-described configuration, before the condenser 3 is removed from the casing 11, the four-way switching valve 2 and the refrigerant circuit (the compressor 1, the electric expansion valve) are controlled by the control device 20. EV) is controlled so that the refrigerant circulation direction of the refrigerant circuit is switched to the reverse cycle, and then the compressor 1 is started to perform a pump-down operation in which the refrigerant is accumulated on the evaporator 4 side. This makes it possible to remove the condenser 3 from the housing 11 in a state where there is no refrigerant in the condenser 3, and the condenser 3 can be easily handled and cleaned. Therefore, the maintenance of the condenser 3 can be easily performed.

  Further, it is not necessary to remove the entire apparatus from the installation place when cleaning the filter 13 and the condenser 3, so that the maintenance time can be greatly shortened and the operating rate of the main machine can be improved.

  Since the conventional liquid cooling device does not include a four-way switching valve, when the condenser is removed and the cleaning is attempted, the refrigerant is recovered by the pump-down operation, and the high-pressure vessel is easy to handle. There is a problem that workability is not good. On the other hand, in the liquid cooling device 10 of 1st Embodiment, it is not necessary to handle as a pressure vessel, handling becomes easy and workability | operativity improves.

  Further, by operating the circulation pump P (liquid pump) during the pump-down operation and circulating the work fluid exchanged by the evaporator 4 through the circulation path, the cold heat of the work fluid flowing through the circulation path is evaporated. 4 can be used for condensing the refrigerant recovered, and the pump down operation time can be shortened.

  The machine tool 100 of the first embodiment is a machine tool such as an NC lathe, a grinding machine, or an NC dedicated machine, or an industrial machine such as a molding machine or a press machine.

[Second Embodiment]
FIG. 7 is a schematic configuration diagram of the liquid cooling device 210 according to the second embodiment of the present disclosure. The liquid cooling device 210 of the second embodiment has the same configuration as the liquid cooling device 10 of the first embodiment except for the evaporator 204.

  As shown in FIG. 7, the liquid cooling apparatus 210 according to the second embodiment includes an evaporator 204 immersed in the working fluid in the oil tank T, and the evaporator 204.

  The evaporator 204 is arrange | positioned under the bottom face of the housing | casing 211 of the liquid cooling device 210, and is formed in the coil shape along the up-down direction. A stirring device 7 for stirring the working fluid in the oil tank T is attached to the lower side of the casing 211. The stirring device 7 includes a motor 7a fixed in the casing 211, a shaft portion 7b extending downward from the motor 7a, and a stirring blade 7c fixed to the tip of the shaft portion 7b. The stirring device 7 is an example of a liquid stirring unit.

  FIG. 8 is a perspective view of the liquid cooling device 210. As shown in FIG. 8, the liquid cooling device 210 is an immersion type liquid cooling device in which the evaporator 204 is immersed in a working fluid stored in the oil tank T. In this liquid cooling device, the working fluid is cooled in the oil tank T. The casing 211 has a vertically long, substantially rectangular parallelepiped shape, and has a plurality of legs 215 that protrude downward from the bottom surface of the casing 211. A suction port 212 is provided on one side surface of the casing 211, and a net-like filter 213 is attached to the suction port 212. In FIG. 8, 214 is a blower outlet.

  On the upper surface of the oil tank T, an opening for inserting the evaporator 204 into the oil tank T is provided. The oil tank T is provided with a circulation pump P. By driving the circulation pump P, the machine fluid discharged from the machine tool 100 is supplied into the oil tank T and cooled again. Is supplied to the machine tool.

  According to the liquid cooling device 210 having the above-described configuration, the control device 20 causes the control device 20 to operate the stirring device 7 (liquid stirring portion) during the pump-down operation, and the oil in which the working fluid circulated by the evaporator 204 is circulated. By stirring the working fluid in the tank T (liquid tank), the cold heat of the working fluid flowing through the circulation path can be efficiently used for condensing the refrigerant recovered in the evaporator 204.

  Further, the liquid cooling device 210 of the second embodiment has the same effect as the liquid cooling device 10 of the first embodiment.

[Third Embodiment]
The liquid cooling device of the third embodiment of the present disclosure has the same configuration as the liquid cooling device of the first embodiment except for the operation of the control device 20. Further, in the maintenance method for the liquid cooling system including the liquid cooling apparatus according to the second embodiment, the method of the first embodiment is not provided in that it does not include a step of precooling the working fluid flowing through the circulation path before performing the pump down operation. It is different from the maintenance method of the liquid cooling system.

  The liquid cooling device 210 of the third embodiment has the same effect as the liquid cooling device 10 of the first embodiment.

  In the first to third embodiments, the liquid cooling devices 10 and 210 that cool the work fluid while circulating the work fluid of the machine tool 100 through the oil tank T have been described. The present invention is not limited to the working fluid, and the present invention may be applied to a liquid cooling device that cools liquids other than grinding fluid and lubricating oil.

  Although specific embodiments of the present disclosure have been described, the present disclosure is not limited to the first to third embodiments described above, and various modifications can be made within the scope of the present disclosure.

DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Four-way switching valve 3 ... Condenser 4,204 ... Evaporator 5 ... Accumulator 6 ... Blower fan 7 ... Stirrer (liquid stirring part)
DESCRIPTION OF SYMBOLS 10,210 ... Liquid cooling device 11, 211 ... Housing | casing 12,212 ... Suction port 13,213 ... Filter 14 ... Outlet port 15,16 ... Pipe connection part (closed part)
DESCRIPTION OF SYMBOLS 20 ... Control apparatus 100 ... Machine tool EV ... Electric expansion valve L1, L2, L3 ... Piping P ... Lubrication pump (liquid pump)
T ... Oil tank (liquid tank)
V1, V2 ... Shut-off valve

Claims (5)

A refrigerant circuit in which a compressor (1), a condenser (3), a decompression mechanism (EV), and an evaporator (4, 204) are connected in an annular shape;
A four-way selector valve (2) for switching the refrigerant circulation direction of the refrigerant circuit from a forward cycle to a reverse cycle;
A control device (20) for controlling the refrigerant circuit and the four-way switching valve (2);
A housing (11, 211) in which the refrigerant circuit, the four-way switching valve (2), and the control device (20) are housed;
The condenser (3) is detachably attached to the casing (11, 211),
The refrigerant circuit has closed portions (V1, V2) on the housing (11, 211) side for closing a refrigerant pipe connected to the condenser (3),
The control device (20) controls the four-way switching valve (2) and the refrigerant circuit before removing the condenser (3) from the housing (11, 211), so that the refrigerant of the refrigerant circuit After switching so that the circulation direction becomes a reverse cycle, the compressor (1) is started to perform a pump-down operation in which refrigerant is accumulated on the evaporator (4, 204) side ( 10,210). The liquid cooling device (10,210) according to claim 1,
A liquid pump (P) for circulating the liquid exchanged by the evaporator (4,204) through a circulation path;
The liquid cooling device (10, 210), wherein the liquid pump (P) is operated during the pump-down operation. The liquid cooling device (210) according to claim 1 or 2,
Provided in a liquid tank (T) in which a liquid to be heat-exchanged in the evaporator (204) circulates, and includes a liquid stirring unit (7) for stirring the liquid in the liquid tank;
The controller (20) controls the liquid agitator (7) to operate the liquid agitator (7) during the pump-down operation. A maintenance method for a liquid cooling system comprising the liquid cooling device (10, 210) according to any one of claims 1 to 3,
Performing a pump-down operation in which the control device (20) accumulates refrigerant on the evaporator (4, 204) side;
After the pump-down operation, closing the closing parts (V1, V2) and removing the condenser (3) from the housing (11, 211);
Washing the condenser (3) removed from the housing (11, 211);
A maintenance method for a liquid cooling system, comprising: attaching the cleaned condenser (3) to the casing (11, 211) and opening the closing parts (V1, V2). In the maintenance method of the liquid cooling system of Claim 4,
A liquid pump (P) for circulating the liquid exchanged by the evaporator (4,204) through a circulation path;
Before the step of performing the pump-down operation, the liquid pump (P) is operated with the four-way switching valve (2) in a state where the refrigerant circulation direction of the refrigerant circuit is a positive cycle, Preliminarily cooling the liquid flowing through the circulation path with the evaporator (4,204),
In the step of performing the pump-down operation, the liquid pump (P) is operated to use the cold heat of the liquid flowing through the circulation path to condense the refrigerant in the evaporator (4, 204). System maintenance method.

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